P3 Really Flashcards
ACIDITY
Acidity is one of the most important components in both grape juice and wine it provides tartness and freshness integral to balance. Scientifically defined as the measure the concentration of hydrogen ions (H+) free in solution
ALCOHOL REDUCTION
High levels of alcohol reduction can be achieved through a range of physical and chemical methods: vacuum distillation, reverse osmosis, electrodialysis (can’t do for organic). More modest reductions are possible by: water additions, earlier harvesting (Forest The Doctor’s Range), blending, and via fermentation choices such as warmer temperatures, open top vessels, and yeast strain (about .5-1 degree dif). Also, whole cluster (can reduce .7-1%)
ASORBIC ACID
“Ascorbic acid is a powerful antioxidant helpful in winemaking as a reinforcement to SO2. Ascorbic acid must be used in conjunction with SO2 or ascorbic acid will react with oxygen and produce hydrogen peroxide which is itself a powerful oxidant. Further, the reaction of ascorbic acid and oxygen causes a product brown in color which impairs the wine’s hue even more than oxidation alone. It is used in white wine production to keep the wines ultra-fresh. Ascorbic acid reacts with oxygen much more rapidly than SO2 alone.
Benefits:
• Ascorbic acid reacts rapidly with oxygen and protects primary aromas and flavors.
Ascorbic acid additions have also been found to reduce pinking in white wines (AWRI studies)
Disadvantages:
• If insufficient free SO2 (<30 mg/l) present, ascorbic acid will react with oxygen to form the powerful oxidative compound hydrogen peroxide.
Administration:
• EU limit is 250 mg/l as additions and 300 mg/l total in finished wine
• Must have free SO2 > 30 mg/l”
BACTERIAL SPOILAGE (MAIN CAUSES)
main causes of bacterial spoilage are lactic acid bacteria (pediococcus, lactobacillis) both cause unwanted odors, flavors, and haze or acetobacter which reacts to form acetic acid and can further react to form ethyl acetate in the presence of oxygen
BAG-IN-BOX
developed in 1970’s to provide larger packing format without the weight and breakage risk of bottles, and the ability to minimize oxygen ingress once opened to extend usage life. Oxygen barrier is provided by thin layer of aluminum between 2 layers of hdPE, or an oxygen barrier made from clear poly vinyl alcohol (PVOH.) Main disadvantage is flex cracking, leakage through spout (tartrate formation/seal failure) or refermentation in packaging. Shelf life 9-12 mos and only 4-6 weeks once opened. Mainly used for entry priced wines but moving upscale and favored format in Skandi monopoly markets for sustainablity benefits. Wine for BIB often transported in bulk and bottled in country of sale to maximize shelf time.
EXAMPLE: Large growth in 2020 (OIV) with volume +12% and value +8% as a response to COVID. Largest importers by value: Sweden, Germany, UK
BENTONITE
a tasteless, montmorillonite clay fining agent with a strong negative charge capable of binding to positively charged proteins (pigments, colloids, enzymes, amino acids) removing them from solution enhancing wine’s protein stability. Bentonite is non-selective and causes aroma, color, and flavor reduction so bench trials must be used to determine optimal dose. It also creates a heavy deposit and related wine loss.
BLUE FINING (Potassium Ferrocyanide)
Potassium ferrocyanide is used to remove copper from wine but is not legal in all markets. Copper residues generally result from Copper Sulfate treatments for excessive Hydrogen Sulfite levels, or agricultural sources. All wines are tested for Copper and Iron! potassium ferrocyanide reacts with copper first then iron so need to have iron residue to confirm there is no cyanide poison in the wine! Copper residue limits 0.5 mg/l US, 1 mg/l EU
BOTTLING
comprehensive term for activities involved in packaging wine into units suitable for final consumption, includes formats such as bottles, cans, bag in box, pouches, and metal kegs.
BRETTANOMYCES BRUXCELLENSIS (BRETT)
Brettanomyces bruxellensis (brett) is a spoilage yeast in wine commonly used in the beer industry. In small amounts it can be considered a complexity element in certain wine styles, but is a fault at higher concentration levels. It is most often associated with wines that have undergone barrel maturation, both red and white, but is most often associated with red wines. Brett needs oxygen and residual sugar to maximize growth and once established in a cellar is difficult to manage. Brett produces three main aroma/flavor compounds 4 EP (ethyl phenol–band aid, sweaty saddle), 4 EG (ethyl guaiacol–smoke spice), and 4 EC (ethyl catechol–horse, barnyard) While strain adaptation has been noted in research it can be controlled by molecular SO2 levels of at least 0.625 mg/l, creating a management challenge for high pH wines. A further risk is the unprotected period wine may have between primary fermentation and MLF. Cellar practices to limit brett risk include; 1) excellent cellar hygiene; 2) SO2 maintenance, 3) cooler cellar temperature; 4) acid adjustment to increase SO2 molecular levels; 5) treating oak barrels with radiant heat, ozone, steam (somewhat debatable effects); 6) avoidance of oak or at least old oak (again debatable); 7) minimizing period between fermentation and MLF; 8)fermenting to dryness followed by filtration to 0.8 microns. If detected via plating or Scorpion panel (PCR test), brett can be treated with chitosan (4g/hl) followed by filtration (generally to at least 0.8 microns, but RdV at 1.0); DMDC to remove the yeasts. Infected wine can only be filtered and then blended to reduce the concentration or treated via reverse osmosis or vacuum distillation, where allowed.
BULK TRANSPORT
Bulk transport involves moving large volumes of finished wine from its region of origin to its end market for packaging and sale. According to the OIV, 16% of annual wine production is transported in bulk (34% of exported wine), and volumes have been steadily increasing over the last decade. The European Union is the largest importer of bulk wine accounting for over half global volumes. Spain, Australia, Chile, Argentina and South Africa are the largest exporting nations meaning most bulk wine travels over long ocean distances crossing the equator and is subject to extended temperature change. Two types of intermodal containers: Rigid ISO steel tanks with a 26,000L capacity; and flexitanks, which are essentially giant polyethylene bladders with an oxygen copolymer barrier, housed in standard shipping containers with a 24,000L capacity. Flexitanks are more abundantly available and dominate volumes. Bulk transport saves 35-40% over shipping in bottle. Also includes transport by truck and train.
CAN
inert, lightweight, recyclable, packaging material for wine. Relies on integrity of vinyl liner which if damaged will cause package failure due to H2S formation and discoloration of wine. Also, packaging material is highly reductive so SO2 additions must be calibrated with this in mind (max 25 ppm free). Growing in popularity due to sustainability and usage ease particularly with younger consumers.
CARBOXYMETHYLCELLULOSE (CMC)
“Carboxyl Methyl Cellulose (CMC) is a crystalline inhibitor derived from wood used to infer cold stability in wine. CMC is derived from cellulose and inhibits potassium tartrate crystal formation. Unlike metatartaric acid, CMC provides a long duration of potassium tartrate crystal inhibition (So African study 2yrs min).
Benefits:
• Does NOT impact on wine pH, unlike cold stabilization
• Does not require the energy expense of cold stabilization (6 cents/liter versus 25 cents to chill)
• Long duration effectivity, but only against potassium tartrates
• Does not strip wine and adds to texture
• No volume loss during stabilization process, or need to rack off deposit, no risk of oxygen introduction
• No expensive equipment required (ion exchanger etc)
Disadvantages:
• Not suitable for red wines as it strips some color, but may be appropriate with rose
• Wine must already be protein stabilized or it may form a haze post CMC use
• Must be administered after fining and before final filtration and be last additive or modification or there is a risk of haze formation.
• CMC is not considered a natural product
• May be difficult to prepare and needs to dissolve and swell in water overnight before dosing. It also needs vigorous stirring to dissolve. Also available in liquid form that eases use.
• Up to five days wait time before final filtration may be required to avoid clogging filters pre-bottling
Administration:
• Must be administered after fining and before final filtration and be last additive or modification or there is a risk of haze formation.
• Requires 24-48 hours after use before wine can be filtered for bottling, 5 days is usual recommendation
• Dose depends on manufacturer—Lafort Celstab product is 10 g/hl maximum”
CASEIN
positively charged fining agent derived from milk protein used primarily for white and rose wines to remove brown pigmentation, off odors, and bitter phenolics. Also reduces Fe levels. Some producers (eg Ch. St. Michelle) use skim milk instead. Can be somewhat successful as treatement to remove brett aromas and flavors as well as smoke taint
CENTRIFUGATION
rapid and aggressive method to clarify highly turbid musts. Expensive and only used in large scale wineries for particularly difficult clarification situations (eg The Wine Group, Modesto)
CHAPTALISATION
addition of cane of beet sugar to fermenting must to increase the potential alcohol level in the final wine. Prohibited in warm EQ climate zones but common in marginal and cool climates. Burgundy, Champagne, UK. Sugar additions are often spread out over the course of fermentation to extend it and add greater aromatic and flavor complexity as well as to slightly stress the yeast to form higher glycerol and round out mouthfeel
CLARIFICATION
basket term for activities that decrease turbidity in juice, must, or finished wine and an essential contributor to wine stability. Clarification involves the removal of insoluble solids and colloids by gravity settling and subsequent racking,or flotation, filtration, fining, and centrifugation
CLARITY
measurement of opacity due to suspended, insoluable, solids in solution measured in NTU (Nephelometric turbidity units)
CLOSURES
container adjuncts necessary to avoid harmful environmental contact to packaged wine and allow ease of access by consumers. Breakdown by type: 18 billion bottles/yr globally 11.5B cork (60%, includes tech corks); 4.5B Screwcap (25%); 2B Synthetics (11%)--Source-Amorim, but Gualla Closures claims 6.5B Screwcaps. OTR range (cc Oxygen/day): Glass ampoule (perfect seal) 0.0 Screwcap, tin/saran liner 0.0001 Agglomerated cork Natural cork 0.0005 (2-3% TCA taint) Screwcap, saranex liner 0.001 Synthetic cork 0.005
CONTACT PROCESS
a more rapid form of cold stabilization for tartrates that involves seeding the precipitation with potassium bitartrate crystals to reduce the energy requirement of the overall process
CONTAMINATED WINE/DEFECTIVE WINE (PREVENTION OF)
wine affected by a potential harmful substance introduced via an external source. This is opposed to a fault which results from an imperfection that was generated within the wine.
CONTRACT BOTTLING
outsourcing of wine packaging to a third party provider either on or off site
CORK TAINT
Wine defect cause by anisole compounds, most notably 2,4,6-trichorolanisole (TCA), produced when airborne fungi metabolize environmental chlorine. Cork taint causes musty smells and or loss of primary aromas. The fungi are insidious and harbour in wood, cork, and packaging materials and thrive in moist cellar conditions. TCA is a fault if detectable, which by humans is at levels as low as 2-3 ppt. Data from the International Wine Challenge and Wine Spectator based on wine samples received estimate 2-7% of all wines have TCA at fault detectable levels. Filtering with a synthetic polymer filter can reduce up to 82% of the compounds according to a study by the ISVV in Bordeaux.
CROSS FLOW FILTRATION
a form of tangential absolute filtration the blocks particles larger than the selected filtration pore size. Pros: Unlike membrane filters, the tangential contact the wine makes on cross-flow filters means they do not clog and can be used even for wines with heavy solids as a fairly rapid and one step filtration option down to sterile levels.Cons: expensive equipment (20K-50K USD), filters have finite life even though they can be cleaned, need scale to justify investment, but mobile systems available too (cost 30 cents/gallon).
Ex: Casella Wine, Yenda, Australia produce over 12 mill 9L cases were early adopter in 2006. Able to get to targeted 0.2 micron absolute pore size and condense four filtration steps into one so despite upfront capital investment needed the savings of 8,000 labor hrs/yr justified it and break even was less than 2 yrs.
DEPOSIT PREVENTION (IMPORTANCE OF)
Short answer 2017–With most wine styles consumers expect, clear, deposit free, condition. The most common deposits in finished wine are tartrate crystals which form as a result of insufficient tartrate stabilization. Cold stabilized too quickly or not a cold enough temperatures, gum arabic or metatartaric acid, mannoprotein additions deter crystal formation but do not remove them from solution, so protection erodes over time. Other deposits: proteins/protein haze–caused by failure to fine out proteins, generally and issue in white wines because in red wine tannins will bind with them–Bentonite is most common protein fining agent. Metals deposits/haze excess copper or iron are rare but arise from vineyard sources (agricultural treatments) or with Copper from excessive use of Copper Sulfite to treat reduction faults. Both will precipitate out if not tested for stability and fined as needed with potassium ferrocyanide (blue fining.) Phenolic/phenolic haze caused by faliure to fine out excessive levels of tannins in red wines, not problematic in ageworthy reds where deposits are expected, but an issue in early drinking styles. Rare with white wines but if found can be treated with PVPP to rid excess phenolics.
DEPTH FILTRATION
uses a fairly thick layer of filtration media such as cellulose pads or diatomaceous earth to trap particles within the maze of channels the media presents. Good method for eliminating a high level of solids because the filter medium presents a large volume of surface area, but the filter can be overwhelmed by excessive pressure, or if a pad leak. Depth filtration only offers a relative pore size and thus cannot be used for sterile filtration.
DIATOMACEOUS EARTH FILTRATION
Diatomaceous earth (‘DE’, also known as Kieselguhr) - matrix for relative/depth filtration of wine derived from microscopic fossilized algae known as diatoms and available in different particle sizes. Airborne hazard for workers at administration.
EXAMPLE: Suduiraut is transitioning from Kieselguhr/diatomaceous earth filtration (pro: fast, loss of <1%; con: residue, oxygen exposure requires more Sulfur) to cross-flow filtration (con: 50% as fast, pro: reduce sulfur, no residue)
DISSOLVED OXYGEN (DO)
oxygen contained within the wine and a source of oxidative fault if excessive. Total DO <1.25 mg/L. White and Rosé Total DO < 1?
DRY GOODS QA/QC
Dry goods include all packaging products or winemaking products . including barrels. From examiners report–A full written procedure put in place so all winery departments understand the process to ensure dry goods are received, stored, and utilized to enable a wine to be produced bottled and store in the correct and safe manner. Wine is a food product and consumer safety is paramount. Dry goods much match any brand specifications. QA?QC systemmust include flow diagrams, HACCP, and be able to pass an annual supplier aud with adequate records. Storage conditions should ensure no damage of contamination.–Few attempted this question…
EGG WHITE
positively charged protein based fining agent primarily used to remove excessive tannins from red wines, fairly gentle but does remove a bit of color and flavor and requires an allergen warning in EU markets.
ELECTRODIALYSIS
Electrodialysis is an expensive selective membrane technique where an electrically charged membrane selectively removes potassium and calcium ions which reduces tartrate crystal precipitation. pH can be controlled with this process. Pros: Uses less energy than cold stabilization; can run continously; wines do not require pre-treatment; don’t have to rack off tank (no DO or wine loss) ; don’t have to warm wine again to allow for safe bottling temperatures; gives winemaker greater control over pH, wine mouthfeel remains intact since no colloids are stripped. Cons: high capital cost (200K USD) so suited to large scale facilities; uses more water than other tartrate stabilization methods and membrane units produce highly acidic wastewater tht must be treated before it can be released. Ex: Nicolas Quille MW, Crimson Wine Group, Napa likes STARS system because he can remove Calcium and Potassium salts without losing tartaric acid in his white wines. He can adjust total acidity and pH without additives which helps him in organic wine production (US market not EU) where lower SO2 additions are needed. He believes this leads to a better quality end product than traditional cold stabilization.
FAULT
A fault is a property that renders the wine a departure from the acceptable norm, or winemaker’s intention. Faults are caused by microbial (yeast, bacteria, fungal, contaminants or enzymes, (brett, VA, acetaldehyde, refermentation, films, biogenic amines, geranium or mouse taint, TCA, oxidation/laccase), chemical (oxidation, reduction, metals haze, protein instability, tartrates) and environmental factors (light strike, smoke taint, heat damage) NB: To limit essays one can argue based on frequency, severity, ease to avoid or treat, or that faults arise from a factor internal to the wine and anything external is a taint and therefore beyond the scope to be considered.
FILTRATION
fundamental, yet polarizing winemaking process that aids in clarification by removing solid particles such as yeast cells, bacteria, and grape solids. Two main categories of filtration are depth and surface (aka absolute.)
FINING
a winemaking clarification technique used to remove particles too small to filter such as colloids and proteins. Imortantly, fining rids wine of protein instabiltiy due to temperature fluctuation. Fining relies on use of an agent opposite in charge to the substance being fined (ie proteins must be fined with - charged agent like bentonite.)
FINING AGENT
protein, mineral , or other chemical substance opposite in charge to the wine substance the winemaker wants to eliminate
